1. Field of the Invention
The present invention relates to compositions and methods for increasing patient compliance with therapies comprising the administration of aldehyde dehydrogenase inhibitors, and for preventing, ameliorating or treating alcoholism. Such compositions and methods may be used to facilitate alcohol cessation, and may comprise a combination of aldehyde dehydrogenase inhibitors and monoamine oxidase inhibitors.
2. Description of the Related Art
Alcohol is a commonly abused drug. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), problematic alcohol use is divided into alcohol abuse and alcohol dependence.
Alcohol abuse involves recurrent alcohol consumption that negatively affects one's life, whereas alcohol dependence includes alcohol abuse and additionally symptoms of tolerance and withdrawal [McRae et al., “Alcohol and Substance Abuse,” In: Advances in the Pathophysiology and Treatment of Psychiatric Disorders: Implications for Internal Medicine, 85(3):779-801 (2001); Swift, R. M., New England J. Med 340:1482-1490 (1999); Kick, S., Hospital Practice 95-106 (1999)]. In 1997, the estimated lifetime prevalence for alcohol abuse was 9.4% and for alcohol dependence was 14.1%, with men having significantly higher rates of dependence than women [McRae et al., supra]. Alcohol abuse and dependence commonly lead to other problems such as alcohol-related violence, motor vehicle accidents, and medical consequences of chronic alcohol ingestion including death [McRae et al., supra; Swift, supra].
One of the pharmacotherapies that have been suggested for treating alcoholism, including facilitating alcohol cessation, is the administration of agents that inhibiting the enzyme aldehyde dehydrogenase (ALDH), an enzyme involved in the removal of acetaldehyde, a toxic metabolite of alcohol. Examples of ALDH inhibitors include, e.g., disulfiram, coprine, cyanamide, 1-aminocyclopropanol (ACP), daidzin, cephalosporins, antidiabetic sulfonyl ureas, metronidazole, and any of their metabolites or analogs exhibiting ALDH-inhibiting activity including, e.g., S-methyl N,N-diethyldithiocarbamate, S-methyl N,N-diethyldithiocarbamate sulfoxide, and S-methyl N,N-diethylthiocarbamate sulfoxide. Patients who consume such inhibitors of ALDH experience mild to severe discomfort if they ingest alcohol. The efficacy of therapies using ALDH inhibitors depends on the patient's own motivation to self-administer the ALDH inhibitors, e.g., oral forms of the inhibitors, or to receive additional therapies, e.g., DEPO forms of disulfiram. In fact, patient compliance is a significant problem with these types of therapies.
Although multiple forms of ALDH exist. ALDH-I (also known as ALDH-2) and ALDH-II (also known as ALDH-1) are the major enzymes responsible for the oxidation of acetaldehyde. ALDH-I has a higher affinity for acetaldehyde than ALDH-II, and is thought to be the primary enzyme involved in alcohol detoxification [Keung, W. M., et al., Proc. Natl. Acad. Sci. USA 95:2198-2203 (1998)]. The discovery that 50% of the Asian population carries a mutation in ALDH-I that inactivates the enzyme, together with the low occurrence of alcohol abuse in this population supports the contention that it is this isozyme of ALDH that is primarily responsible for alcohol detoxification. Recent studies also implicate ALDH-I in the metabolism of monoamine neurotransmitters such as serotonin (5-HT) and dopamine (DA) [Keung, W. M., et al., Proc. Natl. Acad. Sci. USA 95:2198-2203 (1998)].
Disulfiram, also known as tetraethylthioperoxydicarbonic diamide, bis-diethylthiocarbamoyl disulfide, tetraethylthiuram disulfide, Cronetal™, Abstenil™, Stopetyl™, Contrain™, Antadix™, Anietanol™, Exhoran™, ethyl thiurad, Antabuse™, Etabuse™, RO-sulfiram, Abstinyl™, Thiuranide™, Esperal™, Tetradine™, Noxal™, Tetraeti™. [Swift, supra], is a potent irreversible inhibitor of ALDH-II and inhibits ALDH-I only slightly. Recent studies suggest that the inhibition of ALDH-I by disulfiram occurs indirectly via its metabolites, e.g., S-methyl-N,N-diethylthiocarbamate sulfoxide (DETC-MeSO) [Yourick et al., Alcohol 4:463 (1987); Yourick et al., Biochem. Pharmacol. 38:413 (1989); Hart et al., Alcohol 7:165 (1990); Madan et al., Drug Metab. Dispos. 23:1153-1162 (1995)]. Ingestion of alcohol while taking disulfiram results in the accumulation of aldehydes, which causes tachycardia, flushing, diaphoresis, dyspnea, nausea and vomiting (also known collectively as the disulfiram or disulfiram-ethanol reaction).
Although disulfiram has been available in the United States for many decades, patients frequently have difficulty complying with disulfiram treatment therapies. One reason for poor compliance is the lack of motivation for the patient to continue to take disulfiram, that is, other than self-motivation (i.e., there is no positive reinforcement for taking disulfiram). Another reason is because of the discomfort that arises if the patient ingests alcohol during disulfiram therapy [McRae et al., supra; Swift, R. M., supra; Kick, S., supra]. In fact, disulfiram has not proven to be useful in maintaining long-term sobriety [Kick, supra].
Coprine (N5-(hydroxycyclopropyl)-L-glutamine) has been shown to inhibit ALDH via its active metabolite, 1-aminocyclopropanol (ACP). U.S. Pat. No. 4,076,840 describes the synthesis and use of cyclopropyl benzamides, including coprine, for the treatment of alcoholism. In rat studies, coprine effectively suppressed ethanol consumption, and was shown to be a more potent inhibitor of ALDH as compared to disulfiram [Sinclair et al., Adv. Exp. Med. Biol. 132:481-487 (1980); U.S. Pat. No. 4,076,840].
Cyanamide has been described as an alcohol-sensitizing agent that is less toxic than disulfiram [Ferguson, Canad. M.A.J. 74:793-795 (1956); Reilly, Lancet 911-912 (1976)]. Although cyanamide is unable to inhibit either ALDH-I or ALDH-II in vitro, a reactive product of cyanamide catabolism inhibits both isozymes in vivo, indicating that cyanamide inhibits ALDH via a reactive species [DeMaster et al., Biochem. Biophys. Res. Com. 107:1333-1339 (1982)]. Cyanamide has been used for treating alcoholism but has not been approved in the U.S. Citrated calcium cyanamide is marketed in other countries as Temposil™, Dipsane™ and Abstem™, and plain cyanamide is marketed as Colme™ in Spain [See, U.S. Pat. No. 6,255,497].
Daidzin is a selective potent reversible inhibitor of ALDH-I, originally purified from an ancient Chinese herbal treatment for alcohol abuse. Its analogs include daidzein-7-O-[.omega.-carboxynonyl] ether (deczein), daidzein-7-O-[.omega.-carboxyhexyl] ether (hepzein), daidzein-7-O-[.omega.-carboxypentyl] ether (hexzein), daidzein, puerarin, and dicarboxymethyl-daidzein [Keung, Chemico-Bio. Int. 130-132:919-930 (2001)]. U.S. Pat. Nos. 5,204,369; 5,886,028; 6,121,010; and 6,255,497 describe methods for treating alcohol dependence or abuse using these compounds.
One of the major problems associated with therapies using ALDH inhibitors is ensuring patient compliance with the regimen. According to applicant's knowledge, there have been no teachings that suggest pharmacotherapies that adequately address this problem. For example, WO 99/21540 describes the administration of disulfiram in combination with compounds that bind to the D1 and/or D5 receptors and mimic dopamine to reduce craving for addictive substances in mammals. However, WO 99/21540 does not suggest pharmacotherapy for ensuring patient compliance with the regimen, which is important for the success of the treatment.
Another pharmacotherapy that has been suggested for treating alcoholism involves the inhibition of monoamine oxidases (MAOs). MAOs catalyze the oxidation of a variety of monoamines, including epinephrine, norepinephrine, serotonin and dopamine. MAOs are iron containing enzymes that exist as two isozymes A (MAOA) and B (MAOB). Various publications have described treatments for alcoholism using MAOB inhibitors [e.g, WO 92/21333, WO 96/37199]. WO 96/35425 discusses a treatment for alcoholism using a selective MAOB inhibitor in combination with a partial agonist of the 5-TH1A receptor. WO 00/71109 discusses a treatment for alcohol withdrawal symptoms using the MAOB inhibitor desmethylselegiline in combination with a second drug that treats alcohol withdrawal symptoms. U.S. Pat. No. 6,239,181 describes methods for alleviating symptoms associated with alcoholic neuropathy by administering the MAOB inhibitor, selegiline. However, none of the above references teach or suggest the use of MAOB inhibitors in therapies using ALDH inhibitors. Moreover, none of these references teach that MAOB inhibitors have a sustained effect on ensuring patient compliance with other therapies.
The present invention provides a solution for the deficiencies in traditional therapies using ALDH inhibitors to stop, prevent or reduce recidivism, thus, promoting compliance. The present invention also provides unexpectedly new and better compositions and methods for treating diseases that require the self-administration of an ALDH inhibitor.